Lubricating system for sewing machines



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LUBRICATING SYSTEM FOR SEWING MACHINES v Original Fil'ed June 1Q, 1939 5 Sheets-Sheet 5 Patented Apr. 15, 1941 LUBRICATING SYSTEM FOR SEWING MACHINES Nicholaus Knaus, Newark, N. J., assignor to The Singer Manufacturing Company,

Elizabeth,

N. 1., a corporation of New Jersey Original application June 10, 1939, Serial No. 278,393. Divided and this application August 18, 1939, Serial N0. 290,725

Claims.

This invention relates to sewing machines, more particularly of the overedge stitching type using a needle, an under or,needle-loop-taking looper and an overedge looper, all coordinated to sew an overseam encompassing an edge of material presented to the machine.

An object of the invention is to provide the machine with an improved and simplified lubricating system enabling high-speed operation to be maintained without undue wear and tear on the machine.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawings, Fig. 1 is a longitudinal vertical section through a sewing machine embodying the invention. Fig. 2 is a front view of the machine with certain cover.- plates removed to expose the loopers. Fig. 3 is a top plan view of the machine. Fig, 4 is a section on the line 4--4, Fig. 1. Fig. 5 is a transverse vertical section substantially on the line 5-5, Fig. 1. Fig. 6 is a section substantially on the line 65, Fig. 1. Fig. 7 is an elevation of the oil-gauge reflecting liner. Fig. 8 is a section on the line 8--8, Fig. 5. Fig. 9 is an elevation of the inside of the oil-heat radiator with the outside cover-plate removed. Fig. 10 is an elevation of the back mounting plate forthe oil-heat radiator and Fig. 11 is a section on the line II--I I,Fig. 9.

This application is a division of my copending application, Serial No. 278,393, filed June 10, 1939. v

The sewing machine is constructed with a frame including a hollow oi1-tight casing or main compartment I closed below by means of the removable aluminum bottom plate 2. At the left end of the hollow casing I, Fig. 2, is a base extension 3 from which rises the pedestal 4 of a work-supporting horn 5 around which tubular work may be passed for tube-end overseaming operations. The horn 5 projects away from the hollow casing I and the work-return space 5 thereunder is clear of mechanism. To use this horn and the space thereunder, the usual clothplate I, Fig. 3, is swung to the left about its pivot 8, to an open or out-of-the-way position.

J ournaled in the frame bearing bushing 3, Fig.

1, and in the bushing I0 in the internal frame cross-rib II, and also in the end ball bearing I2, is the main-shaft I3 carrying the belt-pulley and hand-wheel I4. The main-shaft I3 is formed, in that portion thereof within the oil-tight casing I and between the bearing bushings 9, I0, with three cranks I5, I6, and II.

The intermediate crank I5, Figs. 1 and 4, which is lubricated directly by splash lubrication, is connected by the pitman I8 to the crank-arm I9 on the hollow rock-shaft 20 journaled in the frame bearing bushing 2| and formed at its outer end with the arm 22 carrying the clamp 23 for the curved eye-pointed needle 24. The pitman I8 carries the downwardly extending oil agitator 25, Fig. 4, which dips into oil in the sump 26;the oil being maintained at the oil-level o in the sump at the bottom of the oil-tight casing I. The bearing between the rock-shaft 20, Fig. 1, and bushing 2| is lubricated by oil-mist which collects or condenses in the internal frame cut 21 and drips into the external groove 28 extending longitudinally of the bushing 2| and through the port 29 to the internal circumferential oil-distributing groove 30.

Cooperating with the needle 24 is the under or needle-loop-taking' looper 3|, Fig. 2. The looper 3| is mounted on the rock-shaft 32 to which is fixed the crank-arm 33, Fig. 1, having at its free end a ball 34 embraced by the lower socketed end of a pitman 35 driven by the crank I5 on the main-shaft I3.

Cooperating with the under looper 3| and needle 24 is. the overedge looper 36 which is secured to a lever 31 fulcrumed on a pin 38 carried by a sleeve 39 which slides on the stationary pin 40 fixed in the frame-lug 4|. The lever 31 is pivoted at 42 to the crank-arm 43 which is fast on the rock-shaft 44 journaled in the frame casing l and has fixed thereto a crank-arm 45 actuated by the pitman 45 from the crank I] on the main-shaft I3.

The hollow frame casing or main compartment has a large window 41, Fig. 2, in its front face for access to the working parts within the cas-.

tween the plate ii and seat 52 are interposed a white reflector sheet 53 and a gasket 54. The reflector sheet is apertured for the four screws and is further apertured at 55 and W in register with the respective ports 51 and 58 leading into the oil-chamber in the casing l. The gasket is diametrically slotted to expose the white sheet reflector 53 back of the bulged portion 50 of the oil gauge window 49. The oil level should be maintained at the halfway mark in the gauge.

On the rear wall of the casing or main compartment l is mounted the oil-heat radiating subcompartment 59 which is preferably a cast aluminum alloy box-like member closed at its rear side by the removable plate 60 formed with heat-radiating ribs or fins 8|. It -will be seen in Fig. 5 that the radiator box 59 constitutes oilstorage means disposed practically wholly above the oil level 0 in the casing I. Also, the box 59 is spaced away from the rear wall of the frame casing to permit circulation of air therebetween. This spacing is provided by screwing the box 59 to a spacer-bar 62 which is itself screwed at 83, Figs. 3 and 5, to the frame casing rear wall.

' The box cover 0 and box 58 are secured together and to the spacer-bar 62 by the three long screws 6, Fig. 3.

The box 59 has fixed in apertures in the wall thereof adjacent the machine, the horizontal spoon-mouthed oil-catching inlet tubes 55, 66, 0 which extend through the spacer-bar 62 into the oil-splash cavity within theframe casing I.

Mounted within the oil-splash cavity in the casing l is the oil-spray-catching shelf or shallow trough 61- which is' disposed horizontally and drains at its opposite ends into the spoon mouthsv of the oil-inlet tubes 65, 66.

The box 59 is formed internally with end lugs 68 bored vertically to provide ducts 69 to conduct the heated incoming oil from the tubes 65, 66 to the bottom of the box and discharge the heated incoming oil into the bottom of the box from whence it will rise and mix with the cooler oil already in the box and be cooled thereby. The

- box 59 is formed with oil-overflow or oil-return holes II which register with similar holes in the spacer-bar 62 and rear wall of the frame casing l and allow cooled oil from the heat-radiator box 59 to flow back into the casing i and return 7 to the sump at the bottom of the latter. The".

lower portions of the walls of these overflow openings II are below the level of the mouths of the oil-splash catchers and 66.

,oil from the spoon-mouthed inlet pipe 65 and conducting oil to any desired be lubricated. I I

Any excess of oil from the feed-eccentrics l8 and trimming mechanism 19 Fig. 1, gravitates to and collects "in the oil-pocket in the baseextension 3 and filters through the screen 831- into the port 82 leading to the felt pad '3 ma pocket 84 in communication with the oil-sump within part or, hearing to the casing I.

The invention is not limited in its application to an overedge sewing machine but may'obviously be applied to any sewing machine having an oiltight casing containing oil which becomes heated in use.

Having thus set forth the nature of the invention what I claim herein is:

1. A sewing machine having a frame including a, hollow oil-tight casing, stitch-forming and work-feeding mechanism incorporated in said frame and including working parts disposed within said casing for oil-splash lubrication, a hollow heat-radiator disposed externally of said casing, a spoon-mouthed conduit extending through a wall of said casing to catch oil splashed in said casing and conduct it by gravity to a discharge point in the lower portion of said heatradiator, said heat-radiator having a return oiloverflow, duct in the upper portion thereof in communication with the space within said casing.

2. The combination with a hollow oil-tight sewing machine frame having a side wall opening, of an oil-heat-radiating vessel detachably closing said opening and having flxed thereto one or more spoon-mouthed oil-catching lead-in tubes projecting into said hollow frame, said vessel also having an oil-overflow opening in register with said sewing machine side-wall opening, and means in said sewing machine frame to splash a supply of oil therein at a level below said side-wall opening. 1

3. The combination with a sewing machine frame having an oil-tight compartment containing a supply of oil, of an oil-heatradiating vessel on said frame and including an oil-splashcatcher having a spoon-mouth exposed to oilmist in said hollow frame and a duct to lead the oil. caught by said mouth into said vessel, said vessel having an oil-overflow opening disposed below the level of the mouth of said oil-splashcatcher and in communication with the space within said hollow sewing machine frame above the oil-level therein.

4. The combination with a sewing machine frame having an oil-tight compartment, of an oil-heat-radiating vessel detachably mounted on said frame and including an oil-splash-catcher fixed thereto and having aspoon-mouth exposed to oil-mist in said hollowirame and a. duct to lead the oil caught by said mouth into said vessel,

said vessel having an oil-overflow opening dis posed below the level of the mouth of said oil- .splash-catcher and in communication with the space within said hollow sewing machine frame.

5. A sewing machine having'a hollow oil-tight frame casing, a horizontal main-shaft and crankdriven connections therewith contained in said casing, oil contained in said casing at a level below said main-shaft, means to splash the oil in said casing, a hollow oil-heat-radiator separate from and mounted on said casing exteriorly of the latter, a gravity fed conduit having an open oil-splash-catching mouth disposed in said frame casing abovethe oil-level therein and draining through a wall of said casing into said oil-heatradiator, and an oil-overflow duct leading from said oil-heat-radiator into said frame-casing above the oil-levelin the latter and below the level of said oil-splash-catching mouth.

NICHOLAUS KNAUS. 

